1. Related Applications
There are no prior applications related hereto filed in this or any foreign country.
2. Field of Invention
My invention relates generally to form ties and tie fasteners for modular concrete forms and more particularly to headless ties and reusable fasteners supported on the ties at two spaced points.
3. Description of Prior Art
Modular reusable forming structures for concrete, especially for use with vertically oriented planar surfaces of some areal extent, have been found desirable in the modern day concrete forming arts. In response to this finding various types of such structures have become known. These known structures all generally provide some sort of larger surface forming element supported by an auxiliary external frame commonly providing vertical columnar elements or so-called `studs` and horizontal beam elements or so-called `whalers`. Initially the surface forming elements were substantially planar and commonly formed of wood, but they have become much more sophisticated and complex in the development of the art and now may be formed from metals, plastics or composite materials oftentimes to particular non-planar configuration and with special structural adaptations. Vertical supporting studs and horizontal beams in the inception were commonly wooden elements but they again have oftentimes devolved into metal or composite elements of one sort or another often of a complex configuration.
Common with these forming structures are wire-like tie rods that hold adjacent form elements together and at the same time maintain surface forming elements in a spaced relationship. In the earlier development of the concrete forming art this function was commonly accomplished with form wire and spacer blocks. These devices have given way to the typical head form tie of present day commerce which provides a rod-like structure sized to give some rigidity and having an end structure with a protuberance spacedly inward of the head to maintain a spacing washer on the inside of a surface forming element and a larger head at the end outside a form to engage some type of fastener. This type of headed tie obviously is limited in its use to a form structure having a particular thickness and since forms commonly do differ in thickness a plurality of groups of form ties of differing lengths may be required to form a single structure. Similarly with a headed form tie the holes carrying the ties must be large enough to allow for passage of the head and since the head of necessity must be larger diametrically than the body of the tie this always leaves holes in the form through which plastic concrete may ooze.
Various releasable fastening devices, and particularly those of the wedge-type as are commonly used with headed form ties, allow for some adjustment of effective fastening length of a tie used in a particular forming structure, but this adjustable feature is not great and not nearly sufficient to allow for all of the possible variations of length of ties that might be required, even in a single structure.
Responsive to this problem my invention provides a headless form tie of indefinite length, having cyclically similar spaced flattened protuberances defined from an initially cylindrical body and that may be cut to any desired length from elongate stock. The configuration defining the flattened protuberances provides a convenient method of severing pieces of form tie to desired lengths by bending or breaking. My tie rod is formed of mild steel material similar to that of the common headed tie rods of present day commerce and may be manufactured at a cost no greater than that of a similar headed tie rod.
My releasable fastener provides support at two spaced points on my tie rod to establish appropriate length and rigidity substantially equal to that of a headed toe rod of the same initial diameter. Various fastening devices have heretofore become known for non-headed tie rods, but these devices in general have not provided a structure so strong as that provided by my invention nor so strong as that of the typical headed form tie. Such prior fasteners for non-headed form ties have not gained ready industry acceptance because of this lack of strength.
My invention is distinguished from the prior art in providing a headless tie rod that may be formed to any desired length, from stock of indeterminate length, and used with pairs of particular releasable fasteners and spacing washers to positionally maintain two opposed cooperating form elements. My tie rod may be conveniently broken to desired length by reason of its somewhat grooved configuration but yet that configuration provides substantially the same tensile strength as the typical cylindrical headed tie rod of the same body diameter. The fastening devices are adjustably positionable along the tie rod and contact it at two spaced points to provide resistance to stress parallel to the rod equal to that of the typical headed form tie of the same initial size. My tie rod structure provides the same use and benefits as obtained from the headed variety of form tie and may generally be used in the same situations as that headed variety of tie. My tie and fastener combination per se is as economical of manufacture as the common headed tie and fasteners of present day commerce and in overall use is more economical than that present system chiefly because of the lower required inventory. My tie and fasteners are synergisticly related to each other in that their various particularized elements combine to provide a functioning unit of an improved nature but yet either element by itself without the other has little, if any, use.